Federal safety investigators worked side by side yesterday with medical examiners, volunteer firefighters, FBI forensics specialists and other authorities to recover the remains of the 50 people killed Thursday near Buffalo in the crash of Continental Connection Flight 3407.

Steven R. Chealander of the National Transportation Safety Board, which now has authority over the crash site, said it would take three or four days to recover the victims' remains. Most will be identified through DNA analysis, he said.

At the crash site -- a house and back yard in the Buffalo suburb of Clarence Center -- teams sorted wrecked landing gear, buried pieces of the dwelling and victims' remains, sometimes working with small excavation instruments to scrape dirt. Chealander described the scene as "organized chaos."

"It's a slow process, but we are making progress," Chealander said.

At the same time, NTSB investigators continued to gather evidence that will help the agency determine what caused the first fatal airline accident in the United States in more than two years. Forty-nine people onboard the Bombardier Q400 turboprop and one person on the ground were killed when the Newark-to-Buffalo flight crashed as it was descending to Buffalo Niagara International Airport in light snow and mist.

Chealander yesterday gave new details of the final minutes of the flight, operated by Manassas-based Colgan Air, based on reports from the cockpit voice and flight data recorders. He said there was no discussion by pilot Marvin Renslow and co-pilot Rebecca Shaw that the nearly new plane's sophisticated anti-icing system was not working properly.

Chealander said the plane's stall warning system kicked in. Additionally, he said the plane, contrary to earlier witness reports, did not strike the house at a steep angle, but that it apparently fell flat onto the house. And he said that the plane was pointed away from the airport when it crashed. He said investigators will convene in Washington at 9 a.m. today to further analyze the data recorders.

On Friday, the NTSB disclosed that the cockpit voice recorder captured Renslow and Shaw talking about ice buildup on the wings and other parts of the plane. The disclosure is viewed as significant because icing has long been viewed as a serious aviation safety problem. Icing caused the crash of a similar plane in similar circumstances in Roselawn, Ind., in 1994, killing 68 people.

Thursday's crash is likely to refocus scrutiny on FAA efforts to improve standards and testing so that planes might better withstand icing conditions. The NTSB and outside safety experts have called for toughening such standards in the years since the Roselawn crash. Investigators blamed ice and lax regulators for that accident, and the NTSB continues to give the FAA an "unacceptable" rating on a majority of icing issues. FAA officials have said the agency has taken steps to fight the dangers caused by icing.

Chealander said that the safety agency is still in its evidence-gathering stage and that it could take up to a year before the cause is fully known.

"I'm warning everyone to not focus on ice," he said. "We talked about ice [on Friday] because the cockpit voice recorder told us the pilots were talking about ice. We don't want to jump to a conclusion."

Across the nation, friends were remembering the crash victims. In the Washington area, former teachers at DeMatha Catholic High School in Hyattsville recalled jazz guitarist Coleman T. Mellett, known as Coley, who died on his way to a performance in Buffalo. Mellett, 34, graduated from DeMatha in 1992 and played with Chuck Mangione's band. He lived in the New York City area.

"I remember he was an amazing talent," said John Mitchell, the band director at DeMatha. "When I met him in the eighth grade, it was obvious he had a lot of natural ability along with great talent. He was a huge part of the life of our school."